TUGBOAT CONTEST-pick the winner!!

Discussion in 'Boat Design' started by tugboat, Apr 15, 2012.


which tug do you like the best ot these three?!

Poll closed Apr 29, 2012.
  1. first tug

  2. second (middle tug)

  3. last tug

  1. tugboat

    tugboat Previous Member

    the following are three steam tugs

    please view attachments for help with vote...I wish that the votes are mainly based on eye pleasing sheer line etc...not on the stats but they are included to help with vote process as well..

    the first tug

    "salty' design from "Reliable steam"
    stretched and scaled to 25 ft x 9 ft 2" beam.

    this tug is a true steam design originally 20 ft x 8 ft. material: steel

    some advantages:
    -double chined hull,
    -can use light steel or wood/epoxy/ply
    - deep draft for good seakeeping ability
    -good sized accomodation space/fuel stowage -
    -room for boiler and low lcb provides for a heavy vertical boiler

    some disadavantages:
    originally designed for 20 ft.
    -unknown variables with scaling.
    - longer build time/weld-up with double chine, and frames.
    -only single screw capable.
    - not really a good work hull due to design parameters.
    - deck level too high therefore deck is not continuous.
    -no tow bit on f'csle.
    - less walkaround deck space-
    -difficult to alight to and from boat.
    -limited screw aperture.

    middle tug

    my design-24 ft x 9.5 ft beam, radiused chine-
    material: fiberglass construction/corecell, FC, steel, or FAL

    some advantages:
    -twin or single screw aperture to 34 inch screw/s.
    -moderate accomodation space,
    - radiused chine offers economical running.
    -easy to build in glass or core cell or fal,
    - low freeboard aft for working lines
    - lots of room for boiler and good space usage for boiler and fuel.
    - lowest cost hull to build of the three.
    -aft deck is good for linehandling and alighting to and from vessel at wharf.

    some disadvantages:
    -smaller than the other two.
    -less accomodations than the 25 ft versions
    - very wet deck--not suited to ocean towing. (vessel will be a great lakes vessel only anyway)
    - more rolling motion than the chined hulls
    - some materials are labour intensive. steel build needs extra tooling and/or farming out of plate work.

    the last tug

    Mal lows "porker" design:

    his hull, my wheelhouse, skegs, accomodations etc. scaled from 27.5 ft to 25 ft.
    beam 9' 11"
    the hull has a rockered flat bottom (very seaworthy)
    material: steel, corecell, wood/epoxy/ply

    some advantages:
    -can be built "beachable" with bilge keels
    -easy build due to flat bottom,
    -unlimited prop aperture
    -husky steel construction
    -fastest of all three builds
    -single or twin screw
    -nice wide beam
    -screw aperture to suit up to 15 deg. shaft angle

    some disadvantages:

    -set-up of build jig difficult
    -most costly to build
    - high degree of shaft angle
    -high freeboard aft(still wet decks)
    - not as easy to handle lines or alight to and from wharfage
    -must be built upside down
    -more prone to seasickness due to the motion of flat hull in seaway
    -little accomodation space
    -shaft angle the most of three designs

    please cast your vote-- i will look at the vote tally in two weeks(april 30th) and the tug with the most votes -gets built....

    This will help with my decision--not because i want it popular but because its a fun way of choosing --i could build any one and be happy so.....

    let me know if i did not add any really important advantages or disadvantages i might have forgotten...:?:
    thanks for the votes!

    Attached Files:

  2. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    I picked the last design as aft deck is not so wet as #2 and although the build may be slower / slightly more difficult it may be left "as original" at 27.5 ft and shows a bit more freeboard - and do the Great lakes get a bit untidy at times? - a long fetch and solid wind could be quite a challenge...

    something like this as power would be totally fantastic (see attached images) 2 different engines were in for "work" at Kawana - Sunshine Coast, Queensland and then sent to their owner in Melbourne ??? Australia... This one I liked most as it was totally home built - the other one was built using pre-cast pieces... Arr why not - here are all the pictures I took...

    Attached Files:

  3. tugboat

    tugboat Previous Member

    that is just a beautiful engine!!
    that engine has been machined beautifully!!
    where is that engine and do you know the specs?

    however because i am "kanjuice marawardi" -my engines would look more like this::p

    Attached Files:

  4. masalai
    Joined: Oct 2007
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    Location: cruising, Australia

    masalai masalai

    Apart from the castings, I would say the builder did EVERYTHING ELSE... My guess is the castings came from USA.

    I took the photos on 8 Sept 2009 I was chasing some stainless steel and High tensile aluminium tube prices and spotted these in the workshop - With a suitable crane truck I would have stolen them... :eek: :eek: :p
  5. tugboat

    tugboat Previous Member

    hmm--they arent Elliot bay castings - thier not "Reliable'"s for sure, definiitely could be a Pop Arnold design from "tiny power" but it seems doubtful. there are a couple other makers but --not many...a couple people are machining them for sale but its not anyone i know.
    might be a british design or even a refurbished old engine that was blasted?...id like to know what the IHP is and the operating pressure , bore and stroke, and rpms...looks big--whats the dimensions?
  6. masalai
    Joined: Oct 2007
    Posts: 6,823
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    Location: cruising, Australia

    masalai masalai

    The tops of the engines were eye height so, around 5ft 6ins high? - I was only there for about 15 minutes and the people there were "reluctant to talk", and wanted me gone so that they could return to work as I did not have appropriate safety gear on........
  7. tugboat

    tugboat Previous Member

    thats a BIG engine! and a double compound too i believe...likely somewhere in the 25-40 hp range i am assuming..this would put it at a tugboat engine or something like a 70 ft passenger vessel--with about a 65-75 inch oversquared prop. what a beaut!! you should have grabbed it|!:D
  8. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 487, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I disagree in that a flat bottom isn't a go sea boat. If you want to get the least motion in a beam sea, then you'll want the bilge turn as low as practical. This means the flat bottom is better then the other types of shapes employed. A "built down" hull has a fairly high bilge turn so it's movement in a sea will be more severe, the same is true of a canoe body. For pitching moments the ends short be short, which tugs typically are anyway. So, an ideal hull form, for comfort in a steep and/or confused seaway is a modest "U" shaped entry, that flattens out to a square or nearly so midship section, than rises to a "V" shaped stern sections.

    Your first boat will not scale well at 25%, which will exponentially increase everything, especially weight, displacement and stability. On the other hand stretching you seem to have stretched the hull by 25%, yet holding the beam at a 15% stretch, which will help considerably with these scaling concerns. You'd still need to crunch some numbers, but it'll be much better than a direct 25% scaling.

    The last boat has the perkiest sheer, which is appropriate for this type of boat. A stack at the back of the pilothouse, rather then standing alone aft of it always looks better to me, not to mention is more secure. The images don't have enough detail for much more than these observations

    Establish an SOR and start crossing off what you absolutely need.
    1 person likes this.
  9. tugboat

    tugboat Previous Member

    I also agree here-I do like the flat bottomed design a lot--the designer has a white paper on the seaworthiness of flat bottomed tugs...he worked on many...
    PAR I had wondered this --since a round bilge would tend to roll more--

    I like the shear line of this tug as well- i prefer mine--its based on the Alden designed 45 ft St tug which has an almost staright shear and is not well defined..but has a nice working area at the counterstern...

    but may i ask--what is the reason a tug needs a more curved shear rather than one that has a gentler curve aft?

    Establish an SOR and start crossing off what you absolutely need.

    Sorry- lost me there--SOR?.i probably know this but dont have the technical name for it yet --
  10. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 487, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    A round bilge isn't necessarily any more tender then a flat bottom. It's the height of the bilge turn, regardless of type. This said, typical round bilges do have a higher bilge turn then flat bottoms, so they tend to be more tender. This coupled with the also typical "built down" hull form of round bilges designs doesn't help this concern any either.

    A tug doesn't need more sheer sweep aft, it just looks good to my eye and these poll questions where mostly aesthetic considerations, so . . .

    Statement Of Requirements is a list of project goals, the design tries to address as best as it can, within the priorities establish therein. It's the only logical way, to find a design well suited to an owner's needs, desires and wish list, within the practicality of possibilities and budget restraints.

    Aesthetics should be low on the list, as you can make pretty much anything, look like something else with styling clues.
  11. tugboat

    tugboat Previous Member

    Thanks Par- I guess my SOR would be first and foremost the classic tug style.
    low freeboard for a close feel to my element- and easy line handling, towing etc. easy to jump to and from the vessel(i know its not one people normally think of) I want the tug to be small enough to build relatively easily and cheaply--it must be twin screw, steam, and it must have enough power to tow or push a larger object than itself at a decent speed. it must be manouverable, very durable, and be unique among boats--
    I like the totally UNYACHT-ish look--so a workboat look with bare minimum in esthetics, brass, stainless, brightwork etc, lighting anything fancy is out!
    i even like a few dings in a steel boat --it looks like its doing its job....and think of it as the Howard Roark style--(read Ayn Rands the fountainhead).

    It must also be minimal maintenance.
    it should have a shallower than usualy draft. for a tug, and it should have bare minimum accomodaitons-(the barge will be the accomodations)
    i want the displ. in the 10000 to 15000 range but no more.
    so form this i designed my middle tug...i like the round bilge design just because it offers a bit more headroom and because the water flows a little better around the hull, making it a nice run to the bottom, however the flat bottomed tug also has that feature...hence it is economical to run...
    i also like the huge amount of deck space since i will watch those nice sunsets from there...
  12. tugboat

    tugboat Previous Member

    oh no--my design is losing...:eek:
  13. masalai
    Joined: Oct 2007
    Posts: 6,823
    Likes: 121, Points: 0, Legacy Rep: 1882
    Location: cruising, Australia

    masalai masalai

    But I reckon #3 looks the best... (for a mini tug) :D :D :eek:
  14. Frosty

    Frosty Previous Member

    I have to agree with everyone too. I prefer the last and that is because im not a fan of shallow free board. Tugs are a very masculine vessel but I was always put off by the lack of freeboard.

    However if your just pushing and pulling in harbours in flat calm water you dont need it. But I stll prefer the last

  15. tugboat

    tugboat Previous Member

    yea for a sailing vessel you want high freeboard but that creates more windage too...less handling ability in strong winds..theres always a tradeoff...

    the free board even on the other tugs would still be a wet deck..but i get what your saying...so many vessels have copied tug lines though...

    almost every designer is influenced by tugs in thier designs...but low freeboard aft- the water simply drains off with the huge scuppers...the north atlantic supply tugs-have enough water on deck to wash over the crew...in the end i like feeling close to my element:) and -i can think of nothing more pleasing than being 18 inches off the deck...thanks Frosty.
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